The Commodore 128 existed in three different major board versions:
The first board was used in the flat 128 and in the plastic-cased 128D.
Then came the 128DCR board, with the floppy controller integrated on the
motherboard. There was also a 128CR (cost-reduced flat 128).

These are the schematic diagrams of the Commodore 128 main board
("flat C128" and C128D in plastic case). They were on eight pages
in the Commodore 128 Programmer's Reference Guide, two pages
containing one engineering sheet.

These are the schematic diagrams of the Commodore 128DCR main board
(metal case C128D with built-in 1571CR floppy controller). The diagrams
were scanned from a 64'er Sonderheft, and they appear to be a copy of
schematic 252451.

According to Nicolas Welte, there is an error on the right half of page 5.
The 74LS14 hex Schmitt-trigger inverter U113, pin 13 is connected to WPRT*
(misprinted WTRT* on U105), which doesn't make any sense. Obviously it
should be connected to STP1 instead, which is three lines more to the right!